Cabinet nail



Feb. 1s, 1964 A. PANZER 3,121,366

CABINET NAIL Filed Aug. 28, 1961 ZNVENTOR. ADOLF PA NZEE' ATTORNEYS United States Patent O Filed Aug. 28, 1961, Ser. No. 134,223 I Claim. (Cl. 85-21) The present invention relates to improvements in a cabinet nail and more particularly to a nail which combines a strong grip with a reduced tendency to split wood.

It is well known that nails should serve their required function of holding wood or the like together, and that they should be relatively inexpensive. Conventionally, nails are made from wire or small round stock by a nail making machine. In such machines, the nails are cut and shaped to form a point on one side of the cut and to form a head on the other side so as to provide a point on one nail and a head on an adjacent nail. By making a series of spaced cuts on the wire or stock and the accompanying shaping, a series of nails are made in an inexpensive way.

Although the above nails have been widely used, they are not suitable for all purposes because of the limitation in the size nail that can be used without any serious likelihood of splitting the wood and the limited holding power of such sizes. Accordingly, it is desirable to improve the holding power in relation to the splitting tendency without undue increase in cost, particularly where the nails are to be used in cabinet making, interior paneiing and the like as is needed in boat making and other such applications.

It is a primary object of this invention to provide a nail which achieves a stronger grip than a conventional round nail of similar size and which simultaneously reduces the internal stresses that cause splitting of wood or whatever body the nail is driven into.

Another object of this invention is to provide a nail of the character described above which is capable of being produced on a conventional nail making machine.

A further object of the invention is to provide a nail which is held firmly in place against relative rotation and which does not work loose.

Still another object of this invention is to provide a nail having all the above mentioned advantages and which is especially suitable for use in line work such as cabinet making.

These and other objects are obtained by my nail which generally comprises side walls provided with longitudinally extending grooves, and longitudinally extending corners formed by the side walls having sharp serrated cutting edges.

Further objects and advantages of the invention will be apparent as the specification continues, and the new and useful features of my cabinet nail will be fully defined in the claim hereto attached.

The preferred form of my invention is illustrated in the accompanying drawing, forming a part of this specification in which:

FIGURE l is a perspective View of a nail of this invention, partly broken away;

FIGURE 2, an enlarged cross-sectional view of FIG- URE 1 taken through four points of the nail and in the plane of line 2-2 in FIGURE l FIGURE 3, an enlarged view of a portion of an embodinient of a nail of the invention having a barbed serrated edge;

FIGURE 4, a plan view of a board showing two nails of the invention driven into the board in two different positions with respect to the grain of the wood and a conventional nail driven into the same board.

While I have shown only the preferred form of my ICC invention, it should be understood that various changes or modications may be made within the scope of the claim hereto attached, without departing from the spirit of the invention.

Referring to the drawing in detail, there is shown a nail 11 having side walls 12 provided with longitudinally extending grooves 13 and longitudinally extending corners or edges 14 formed by the junctures of adjacent side walls. The grooves are formed by making the side Walls in concave configuration.

In general, any concave form is satisfactory but in order to keep the nail driving straight and to balance stresses, it is preferred that the surfaces be symmetrical and curvilinear. Thus the surface should be substantially cylindrical and dened in cross-section a line which is an arc of a circle, ellipse, parabola, hyperbola or the like. It is also important to use a concave surface to give sharpness to the edges 14.

The corners or edges 14 are serrated with teeth 16 and are suliiciently sharp to provide a cutting edge. The teeth may be of any saw-toothed configuration, but in a preferred form the teeth are barbed by having an upwardly extending point 17 as shown in FIGURE 3. Each tooth is defined by an upper surface 29 and a lower surface 14. Both surfaces slope outwardly and upwardly toward the plane of head 22 so as to terminate in the point 17. As indicated above, the teeth provide the double function of cutting wood fibers to reduce internal stresses and gripping the wood to provide better holding power. The barbed form is especially good for providing: a hold on the wood, making it difficult, if not impossible for the nail to pull or work out.

The present nail preferably has four sides as shown in FIGURE 2, but it is also within the scope of the invention to use three or even five sides, if desired. Four sides are preferred to three because the grain of the wood is cut more symmetrically for different positions of the nail and the shank is stronger for a given size of nail than in the three sided configuration. However, four sides are preferred to five or more because nails with more than four sides are too circular in configuration and hence have too much tendency to rotate loose. Four sides are also easily formed with opposed pairs of rollers or the like.

As shown in FIGURES 1 and 3, the side walls 12 may have smooth surfaces. Such a form allows the nail to slide easily in place as it is driven in, as well as to guide it in as explained above However, it is within the ambit of the invention to include lateral cuts or notches or the like on the concave surface, if desired. In such a case, some additional holding power is provided by the notches.

At the lower end of the nail 11, there is provided a terminal point 18 formed by surfaces 19 in bevelled angular relation to the side walls 12. Thus, the number of surfaces .19 correspond to the number of walls 12, and the cutting edges 21 formed at the intersections of adjacent surfaces 19 are continuous with corners or serrated cutting edges 14. Accordingly, as the nail is driven in, the cutting edges travel vertically through the cut, and excessive cuts are not made.

At the top of the nail is a head 22 which may be of any convenient form, such as the conventional disc-shaped circular head shown in FIGURE l. The head provides a flat striking surface for the hammer and may have a ange 23 so as to provide a hold in the event that the nail is to be removed. However, it will be appreciated that when long portions of the body of the nail are driven in, the hold is often so strong that removal cannot be effected without danger of breaking the nail.

In FIGURE 4, there is shown a board with nail 11 driven therein with the side walls 12 parallel and perpendicular to the grain at A. At B, nail 11 is driven in with the surfaces 12 at a bias to the grain, and at C, there is shown a round nail 24 driven into the same board. As shown in the drawing, the nail at A cuts the wood at 25 and the nail at B cuts the wood at 26. In both cases internal stresses that tend to split the wood are reduced. However, at C there is shown a wedging action forcing apart the uncut bers of the grain so that there is a strong tendency to split with the grain as at 27.

In addition to the reduced tendency of the present nail toward causing splitting, a more positive grip is obtained by fthe tendency of the cut wood fiber ends that are pushed sideways to spring back into the V-shaped spaces 2S between teeth V16 and hold the nail against removal. The square configuration of the nail prevents rotation of the nail in the wood, thus-cooperating with the teeth 16 in preventing the nail from working loose.

Another important feature of the invention is that it may be cut and the head formed by a conventional nail making machine. Compared to the usual process of running a round wire through the machine, a wire is passed through which has been previously shaped with side walls 12, grooves 13 and cutting edges 14 equipped with teeth 16. The side walls and grooves may be made with opposed forming rollers or similar tools. The serrated edges may also be formed by rollers or by other means such as stamping or the method used to form teeth on a file blank. All of these operations are well known to machine designers and various embodiments of the nail incorporating the described structural features may be made as desired.

From the foregoing, it will be apparent that I have provided an improved cabinet nail possessing a novel combination of cofunctioning structural features which sub stantially eliminate splitting of the wood and working loose of the nail, the structural features being such as to permit economical manufacture on existing types of machinery.

I claim:

A cabinet nail of a character described, comprising a straight shank having a hat circular enlarged head at one end and a terminal point at the other end, the shank hav ing two pairs of opposing lengthwise arcuate concave surfaces defining two pairs of grooves in the sides thereof which extend substantially the entire length of said shank, the outer edges of adjacent concave surfaces meeting and terminating so as to form sharp edges between and in the contour of the grooves, the grooves being relatively shallow with respect to the thickness of the shank so as to leave an intact central body portion with a minimum thickness greatly in excess of the maximum depth of the grooves, and the edges being serrated so as to dene teeth extending throughout the entire length of each edge, each tooth being defined by upper and lower at surfaces each of which slope upwardly toward the plane of said iiat head and outwardly relatively to the longitudinal axis of the nail, each of said flat surfaces having a pair of arcuate edges defined by the intersection of the ilat surface with a pair of said concave surfaces, all of the arcuate edges of each tooth converging to a common point, adjacent flat surfaces of adjacent teeth converging together to form V-shaped recesses between each pair of adjacent teeth, said nail having an end portion of pyramid shape, the sides of said end portion merging smoothly with the surfaces of said grooves, and said terminal point being at the apex of said end portion.

References Cited in the le of this patent UNITED STATES PATENTS 635,846 Dice Oct. 31, 1899 895,080 Eisenreich Aug. 4, 1908 1,360,344 Ingraham a- Nov. 30, 1920 FOREIGN PATENTS 423,077 France Feb. 6, 1911 1,487 Great Britain June 13, 1863 

